Lightning arrester



Aug- 29 l1939- J. s. BAKER 2,171,351

' `LIGHTNING ARRESTER Filed Jan. 20, 1938 ggf.

Y J A Patented Aug. 29, 1939 UNITED STATES PATENT OFFICE LIGHTNING ARRESTER of Illinois Application January 20, 1938, Serial No. 185,799

8 Claims.

This invention relates to lightning arresters or gap dischargers and is directed more particularly to improved lightning arresters or discharge gap units and their method of assembly.

4Such lightning arresters or discharge gap units are designed largely for use in connection with comparatively low voltage electric circuits, such as telephone, telegraph and signal systems to provide for high potential discharges without permanently grounding the line. However, the present invention is not to be limited to such uses solely, because the construction of the arrester and the method of assembly of its parts, as herein disclosed, may be used generally elsewhere.

One object of this invention is to provide an improved lightning arrester of rugged construction that may be accurately made and so assembled as to be free of maintenance expense- A further object of the invention is to provide a lightning arrester of the character described having its parts susceptible to rapid commercial production in large quantities at low cost, and to provide a method of assembly that accurately predetermines the discharge gap thereof. Y

A further object of the invention resides in the production of an improved lightning arrester which is composed of few parts that are simple in construction and capable of being assembled by a method assuring at all times accurate forma- 3 tion of the discharge gap.

A still further object of the invention resides necessary to secure and maintain such uniform discharge gap.

Further objects and advantages of the invention will be apparent from the following detail description when taken in connection with the accompanying drawing forming a part hereof.

In the drawing:

Figure 1 is a detail view illustrating one form of embodiment of several lightning arresters embodying the present invention Fig. 2 is an enlarged sectional view of one of the lightning arresters shown in Fig. l;

Fig. 3 is a longitudinal sectional view of the same;

Fig. 4 is a cross section on lines 4-4 of 5 Fig. 3;

Fig. 5 is a plan View of the same at a reduced scale; and,

Figs. 6 and 7 illustrate the steps of the method employed to assemble the parts to secure a dis- 10 charge gap of predetermined dimension.

As illustrated in the drawing, the lightning arrester or gap discharge unit A may be associated, in one of its embodiments, with a carbon block B carried and held upon grounding plates 15 2 by spring contact lingers 3. This construction or arrangement of parts is well understood in central ofce protector equipment used between the line and switchboard circuits in telephone, telegraph and signal systems. 20

In this arrangement, a discharge gap l is provided between carbon plate B serving as one electrode and the edge 5 of a discharger blade 6 serving as the other electrode whereby to protect the circuit against high potential. 25

To secure an accurate and uniform discharge gap 4 of a predetermined dimension, discharger blade 6 is mounted within and carried by an insulating block 'I. insulating block 'l is provided with a central opening 8 that extends there- 30 through between opposed faces 9 and ID. Opening 8 is preferably formed to provide a pocket II surrounded by a marginal flange or seat I 2 which engages the outer edge of carbon block B as shown in Fig 2. In effect marginal seat I2 comprises face 9. Opening 8 extends upwardly through insulating block I and is provided with opposite shoulders I3 and I 4. Discharger blade is formed to have cooperating shoulders I5 and I6 which bear against shoulders I3 and I4. Dis- 40 charger blade 6 continues with a reduced neck il that extends beyond opening 8. Face IIl of insulating block 'I may be of double channel formation so that spring contact fingers 3 may ride in upper channel I9. Adequate space may be tliere- 45 by provided by virtue of lower channel I 9 to allow neck Il to extend thereinto and be so locked in position by a riveting operation of the outer corners thereof, as illustrated in Fig. 7, as to hold discharger blade 6 firmly in insulating block and not only provide but maintain discharge gap 4, as well as secure a iirm electrical connection with spring finger 3, as will be more fully described.

To this end, a conductor plate I8 is placed upon face l0 of insulating block l. It is provided with of blade 6.

an opening through which reduced neck I1 extends. The riveting action referred to is, in fact, made in connection with conductor plate I8 whereby there is secured an effective electrical connection between plate I8 and discharger blade 6 and said parts are securely locked together to provide and maintain discharge gap 4.

Insulating block 7 is simple and may be readily molded. Blade 6 and plate I8 may be simple stampings. These three parts may be assembled o1' mantled in the manner described by a single stroke of a press. This may be accomplished by placing discharger blade 6 edgewise in a holder or rigid support 25. Support 25 is adapted to project a given distance above a .die plate 26 having a at smooth surface 21. Insulating block 1 is then placed over discharger blade 6 so that the latter extends upwardly in opening 8. Conductor plate I8 is then placed in position with lneck I1 of discharger blade 6 projecting therethrough, as shown in Fig. 6. A simple form of punch may be employed to permanently set or lock .discharger blade 6 in insulating block 1. This punch may comprise the outer compression members 28 and the inner clinching members 29. Fig. 6 shows the parts before the stroke. Compression members 28 exert pressure against plate I8 and insulating block 1 until face 9 or seat I2 is brought against the smooth at surface 21 of die 26. Shoulders I3 and I4 are pressed against shoulders I5 and I6 of discharger blade'. It is apparent that shoulders I5 and I6 are thereby pressed upon shoulders I3 and I4 and the former are forced downwardly, as shown in Fig. '1, depending upon the distance between surface 21 of die 26 and seat I2 of block 1 before the stroke of compression members 28. During this operation, discharger blade 6 is firmly held upon support 25.

The pressure is thereafter continued through the clinching members 29 to cause the corners 36 Yof reduced neck I1 of discharger blade 6 to be sheared and bent downwardly against plate IB to form securing rivets, as shown in Fig. '1.

From the foregoing description it will be apparent that .discharge gap 4 will be of predetermined dimension and will depend upon the distance rigid support 25 extends above surface 21. The upper part of support 25 may be U-shaped to receive firmly the lo-wer edge 5 of blade 6, as shown in Figs. 6 and 7.

This method of assembling the parts is simple and inexpensive, and assures that discharge gap 4 will be uniform from end to end between the face of carbon block B and the discharge edge 5 Insulating block 1 will be forced downwardly by pressure exerted through compression members 28 until its face 9 or seat I2 engages surface 21. Shoulders I5 and I6 are therefore forced upon shoulders I3 and I4, depending upon the dimension of the spark gap or discharge gap desired. In the same stroke of the press discharger blade 6 is immediately locked mechanically by the aforesaid riveting operation whereby all three parts are securely locked together into a unit. The accuracy with which spark gap 4 may be made by this method of assembly will be apparent from the description giv- V en. The operation is simple and very effective.

It will be understood that this mode of assem- 'vbly to secure an accurately formed discharge gap of predetermined dimension may be generally employed and is not to be limited to a unit of a type described, or to a lightning arrester used as part of protective equipment in telephone circuits. Y Y Y The three parts comprising the lightning arrester described, to wit, insulating block 1, discharger blade 6 and conductor plate I8 are each simply formed and are susceptible to rapid commercial production in large quantities. Their construction readily lends themselves to easy and rapid assembly by a method that is foolproof in character and assures the formation of a discharge gap between the space discharge electrodes that is uniform and of predetermined dimension, and eliminates tedious and expensive grinding operations that were hereto-fore required. The discharge gap may be readily Varied in dimension by a corresponding change in position of rigid support 25 with respect to surface 21.

Without further elaboration, the foregoing will so fully explain the gist of my invention that others may, by applying current knowledge, readily adopt the same for use under varying conditions of service, without eliminating certain features, which may properly be said to constitute the essential items of novelty involved, which items are intended to be defined and secured to me by the following claims.

I claim:

1. The method of assembling a discharger blade within an insulating block of a lightning arrester to provide a discharge gap of a predetermined dimension comprising mounting the discharger blade upon a support projecting above a surface a distance equal to that of the discharge gap to be formed, then placing the insulating block over and upon the discharger blade so that the latter enters an opening extending through the insulating block and projects beyond the opening at the opposite side of the insulating block, applying a pressure against the insulating block at said opposite side until the insulating block has been forced against said surface, and applying a pressure against that portion of the discharger blade projecting beyond said opening to form a riveting connection between the discharger blade and the insulating block.

2. The method of assembling a discharger blade within an insulating block of a lightning arrester to provide a discharge gap of a predetermined dimension comprising mounting the discharger blade upon a support projecting above a surface a distance equal to that of the discharge gap to be formed, then placing the insulating block with a conductor plate on the opposite side over and upon the discharger blade so that the latter enters and projects beyond an opening extending through the insulating block and the conductor blade, applying a pressure be* tween the insulating block and conduct-or plate and the discharger blade until the insulating block has beenl forced against said surface, and applying a pressure against that portion of the discharger blade projecting beyond the opening in the conductor plate to form a riveting connection between the discharger blade and the conductor plate to lock said parts together.

3. A lightning arrester comprising an insulating block having an. irregular opening extending therethrough, a discharger blade in said opening, relatively yieldable shoulders on said discharger blade and on said insulating block within said irregular opening, said shoulders on said insulating block being pressed upon said shoulders on said discharger blade, the lower edge of said discharger blade being thereby spaced a predetermined distance within said opening from one side of said insulating block to form a discharge gap, and means for locking said discharger blade to said insulating block.

4. A lightning arrester comprising an insulating block having an irregular opening extending therethrough between opposed faces and a shoulder formed along the wall of said opening, a discharger blade in said opening having a shoulder formed thereon engaging said shoulder on said insulating block whereby to limit the position of said discharger blade in said opening to form a discharge gap at one of said opposed faces by the distance between said face and one edge of said discharger blade, a conductor plate positioned upon the other of said opposed faces, and means formed at the opposite edge of said discharger blade for locking the latter to said conductor plate.

5. A lightning arrester comprising an insulating block having an opening therein, a discharger blade in said opening with one edge of said discharger blade exposed, and means for predetermining the distance between said exposed edge and an adjacent face of said insulating block to form a discharge gap of predetermined dimension, said means comprising a shoulder on said discharger blade bindingly engaging in pressed relation the wall of said opening in said insulating block, and means for locking said discharger blade to said block in said relation including an apertured plate positioned upon the opposite face of said insulating block and through which apertured plate the opposite end of said discharger blade projects, and turned down portions on said opposite edge of said discharger blade for engaging against said plate.

6. The method of making and assembling the parts of a lightning arrester to provide a discharge gap of a predetermined dimension which comprises providing a shoulder upon an insulation block and a shoulder upon a discharger blade that are relatively yieldable with respect to each other, mounting the discharger blade upon a support projecting above a surface a distance equal to that of the discharge gap to be formed, arranging said block in assembled relation with respect to said discharger blade so as to bring said shoulders against each other, applying a pressure between said discharger blade and said insulating block to cause said shoulders to yield relative to each other until said insulating block is brought against said surface, and locking said discharger blade and said insulating block together while said shoulders remain in yielding relation.

'7. The method of predetermining the discharge gap of a lightning arrester which comprises providing relatively yieldable shoulders upon a discharger blade and an insulation block, positioning said discharger blade and said insulation block in assembled relation with said shoulders abutting each other, applying a pressure between said discharger blade and said insulation block to cause said shoulders to yield relative to each other until one edge of said discharger blade is spaced a predetermined distance with respect to one side of said insulation block, and locking said discharger blade and said insulation blade together with said shoulders yieldably pressed together.

8. A lightning arrester comprising an insulating block, a discharger blade, and means for locking said discharger blade in fixed relation with respect to said insulating block to provide a predetermined discharge gap for said discharger blade, said means including a metal plate held upon the upper face of said insulating block by rivets, said rivets being formed out oi' metal shoulders projecting from said discharger blade and extending through said plate, there being opposing metal shoulders on said discharger blade and within said insulating block to provide a locking relation between the parts.

JOHN S. BAKER.

CERTIFICATE OF CORRECTION.

Patent No. 2,171,551. August 29, 1959.

JOHN S. BAKER.

It is hereby certified that error lappears in the printed specification of the above numbered patent requiring correction as follows: 'Page 5, second column, line 25, claim?, for the word "blade" second occurrence, read block; and that the said Letters Patent should vbe read with this correction therein that the same may. conform to the record of the case in the Patent Office.

Signed and sealed this 10th day of' October, A. D. 1959.

Henry Ven Arsdale,

(Seal) Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION.

Patent No. 2,l7l,55l. August 29, l959.

JOHN S. BAKER.

It isv hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: 'Page 5, second column, line 25, claim?, for the word "blade" second occurrence, read block; and that the said Letters Patent should vbe read with this correction therein that the same may. conform to lthe record of the case in the Patent Office.

Signed and sealed Athis 10th day of October, A. D. 1959.

Henry Van Arsdale, (Seal) Acting Commissioner ofI Patents. 

